Note: small sample size !Poll Methodology
The Wall Street Journal/NBC News poll was based on nationwide telephone interviews of 1,000 adults, including 350 respondents who use only a cellphone. It was conducted from June 14-18, 2015, by the polling organizations of Bill McInturff at Public Opinion Strategies and Fred Yang at Hart Research Associates. Individuals were selected proportionate to the nation’s population in accordance with a probability sample design that gives all landline telephone numbers, listed and unlisted, an equal chance to be included. Adults age 18 or over were selected by a systematic procedure to provide a balance of respondents by sex. The cellphone sample was drawn from a list of cellphone users nationally. Of the 1,000 interviews, 350 respondents were reached on a cellphone and screened to ensure their cellphone was the only phone they had. In addition, 38 respondents were reached on a cellphone but reported also having a landline. Overall, the data’s margin of error is plus or minus 3.1 percentage points. The margin of error for Republican primary voters is plus or minus 6.38 percentage points.
http://www.wsj.com/articles/jeb-bush-marco-rubio-solidify-front-runner-status-1434945661
